The use of the word rank for Navy enlisted personnel is incorrect. The term is rate.. The rating badge is a combination of rate (pay grade, as indicated by the chevrons) and rating (occupational specialty, as indicated by the symbol just above the chevrons).
Neurons are nerve cells that are constantly sending signals to your brain, muscles and glands. You have over 100 billion neurons in your brain sending signals. The signals help the different parts of your body communicate with each other.
Neurons communicate at structures called synapses in a process called synaptic transmission. The synapse consists of the two neurons, one of which is sending information to the other. The sending neuron is known as the pre-synaptic neuron (i.e. before the synapse) while the receiving neuron is known as the post-synaptic neuron (i.e. after the synapse). Although the flow of information around the brain is achieved by electrical activity, communication between neurons is a chemical process.